This invention relates to improvements in or relating to the monitoring of constituents of sheet material, in particular the on-line monitoring of additive constituents of cigarette paper.
It is customary in research and development work in the tobacco industry to measure a number of cigarette paper additives such as calcium carbonate, sodium, potassium, magnesium and mixed sodium and potassium citrates, and monoammonium and disodium phosphate. It is for instance commonplace in research and development experiments to analyze paper before making and before smoking in order to minimize retests.
Calcium carbonate is a filler and affects air permeability and burn rate of cigarette paper, while citrates affect burn rate and phosphates affect ash characteristics. In many research and development applications values of citrate and carbonate are among the most requested analytical data.
Carbonate is currently analyzed by acid/base titration or carbonate electrode. Citrate is analyzed by pyridine/acetic anhydride reaction or by using permanganate titration or metal analysis methods. Most methods thus measure the anion only and additive weight percentage is calculated using assumed cations.
It is seen that there is a need for a rapid automated system for paper additives analysis with immediate feedback of results and portability for siting in areas where fast data feedback can be used most effectively.